1. Technical Field
Various embodiments may generally relate to a semiconductor integrated apparatus, and more particularly, to a resistance variable memory apparatus and circuit and method of operating the resistance variable memory apparatus.
2. Related Art
In general, resistance variable memory apparatuses may be next-generation memory apparatuses having advantages relating to low-costs, random access, high-speed operations, low power-consumption, and nonvolatility.
The resistance variable memory apparatuses may be a memory apparatus in which a data storage material layer is arranged between a pair of electrodes. The data is stored through change in a resistance state of the data storage material layer by an applied current or voltage.
A phase-change random access memory (PRAM) as the resistance variable memory apparatus may basically be configured of an access element and a data storage material layer configured of a phase-change material. When a preset voltage is applied between a word line and a bit line to write (program) data in the PRAM, a write current may be applied to the data storage material layer to change a resistance state of the data storage material layer.
The disturbance that the resistance state of the data storage material constituting the resistance variable memory apparatus is changed according to neighboring environment such as temperature, heat generated in a write operation, an elapse time after the write, and the like may be represented. Read/write margins may be reduced due to the disturbance, and thus the data retention time may be reduced.
In particular, the heat generated in the write operation of the memory cell of the PCRAM may affect neighboring memory cells and when the write operation is performed on one memory cell more than a present number of times, the soft error may occur due to changes in the resistance values of the neighboring memory cells.